Electric circuit controlling device



July 7, 1942. J. G. JACKSON ETIAL 2,289,122

ELECTRIC CIRCUIT CONTROLLING DEVICE Filed May 1, 1937 4 Sheets-Sheet l IN V EN TORS.

July 7, 1942. J. G. JACKSON ETAL 2,239,122

ELECTRIC CIRCUIT CONTROLLING DEVICE Filed May 1, 1957 Y 4 Sheets-Sheet 2 IN V EN TORS.

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y 7, 1942. J. G. JACKSON ETAL 2,289,122

ELECTRIC CIRCUIT CONTROLLING DEVICE Filed May 1, 1957 4 Sheets-Sheet 4 J C Q. Q Q

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Patented July 7, 1942 I 2,289,122 ELECTRIC CIRCUIT CONTROLLING DEVICE John G. Jackson and Ralph H. Kingdon, Detroit,

Mich., assignors to Square D Company, Detro Mich, a corporation of Michigan Application May 1, 1937, Serial No. 140,205

12 Claims.

Thi invention relates to electric circuit controlling devices of the type employing a removable carrier upon which cartridge fuse receiving means is mounted and in one embodiment constitutes an improvement upon, or modification of, the fuse box described and claimed'in applicants Patent No. 1,930,428, granted October 10, 1933.

One object of the present invention is to provide an improved form of electric circuit control device of the type described above.

Another object of the invention is to provide a simplified and economical arrangement for supporting an electrical conductor.

Another object of the invention is to provide an improved enclosure for an electrical circuit controlling device.

Another object of the invention is to provide electric circuit control device embodying a generally cup-shaped base and a fuse carrying cover or plug for the base, in which the carrier is pro- 1 vided with an integrally molded manual operating means, and/or in which the carrier or plug is provided with ventilating openings to aid in dissipating heat generating within the base and which may be rendered relatively inaccessible or shielded by the manual handle.

Another object of the invention is to provide a supporting means for a rigid electrical conductor, preferably of strap or plate-like form upon an insulating base in which the insulating base is provided with abutment means engaging one end of the conductor and in which screw means is provided for another point on the conductor to prevent movement of the conductor in a direction to disengage it from the abutment so that a relatively long conductor may be rigidly supported by means of a single screw.

Another object of the invention is to provide an improved enclosure for an electric circuit control device having a cover made up of parts hinged respectively at the top, bottom, and side of the box with the top and bottom cover sections ordinarily remaining in place to shield live parts within the enclosure, and with the central section readily openable for manual access to manipulable parts.

Other objects and features of the invention will be readily apparent to those skilled in the art from the following specification and appended drawings illustrating certain preferred embodiments of the invention in which:

Figure 1 is a front elevational view with cover portions shown open in dotted lines.

Figure 2 is an enlarged vertical sectional view on 11-11 of Figure 3.

Figure 3 is a sectional view on line IIIIII of Figure 2.

Figure 4 is a sectional view on IV1V of Figure 5.

Figure 5 is a sectional view on V-V of Figure 3.

Figure 6 is a sectional view on VI-VI of Figure 2.

Figure 'I is a sectional view on VII-VII of Figure 4.

Referring to the drawings, i represents an enclosing box receiving the electric circuit controlling instrumentality and provided at the top and bottom thereof with hinged cover flap sections 2 and 3, and with a central cover section t hinged to a side wall of the box with the three sections co-operating to form a complete cover for the front of the box. To the side wall of the box at which the cover 4 is hinged, is mounted a supporting plate 5 of general U-shape with its legs engaging opposite side walls of the box. The leg of the U remote from the hinged mounting is provided with studs 6 which are received within co-operating slots in the adjacent side wall of the box to limit the interior position of the supporting pan and which, when tightened, retain the pan securely within the box. The top and bottom cover flaps, 2 and 3, are provided with studs 1 normally engageable with the side wall of the box for maintaining these portions of the cover in closed position. The cover section 4 is maintained in place by a conventional releasable latching means 8.

Upon the pan 5 is mounted an insulating base 9 formed as herein shown with two major sockets l I, each of which is adapted to receive a fuse carrier carrying two cartridge fuses and with four plug type fuse receptacles It. It is, of course, to be understood that the base may be formed with only a, single, or any number of sockets, and that the plug fuse receptacles may be omitted entirely, or may be of any numberdesired. The sockets H are, provided with central vertically extending ribs I3 upon either side of which and at top and bottom, are mounted stationary contact elements ill of U shape and having their legs extending within slots in the base a more fully described and claimed in the aforementioned patent. The fuse carriers are embodied by insulating blocks l4 having as a part thereof an integrally molded transversely extending handle portion l5. The back faces of carriers it are provided with central vertically extending ribs H5 at either side of which are mounted combined fuse clip and contacts l'l adapted to receive cartridge fuses and to co-operate with the stationary conengage therewith. semble the carrier with the base with the circuit tacts I 0, also as more fully described in the aforementioned patent. Each carrier I4 is provided with a pair of ventilating openings I8 disposed in of the; base an ]the back wall ofjcarrier- I4 and the 'projections13'and l6. "These ventilating openings are located opposite the insulatmg or barrel portion of the cartridge fuse, whichjiwill ordinarily be the portion. of the fuse-apt to attain the highest temperature, and serve to reduce" the heat rise within the-v'device-"which gm ight otherwise take place duesmto -retaine dheat.::At; the same time, the positioning of the*ventilating openings o posite the mid portions of the.

single stud adjacent one end of the strap. While this arrangement is herein specifically shown as accomplished by means of projecting portions 23, this portion of applicants invention contemplates broadly the provision of interlocking surfaces on the base receiving one end of a conducting strap and preventing movement of that end "of thefconductor', except {one direction, together with a retaining mea'nsfor another point on the conductor to prevent movement in such direction.- ...In.thespeciflccircuit arrangement, as herein "illustrated, the two terminals at the upper left w-hand'side of thebase in Figure 3 are intended for: the reception of the incoming line, and the two terminals at the top right hand side of the base are intended for a tap off to an electric fuses and their shielding hymn-e handle l5 pre vents ready access to live parts of the device. ..To perform the switching operation, the

3 handle l5"'is grasped and the carrier l4 bodily removed from the socket, ll in the base, thus interrupting current between the stationary con tacts Ill and the portions of the combined clip I! If it is desired to re-as- 180 to reverse top for bottom and the carrier is again inserted. in the socket in the base with the same face directed toward the base and with the cartridge fuses receivable within the sockets. However, in this latter position, means is provided for preventing movement of the carrier entirely within the socket in order to prevent engagement of the co-operating contact portions. The carrier I4 is provided with a pin which, in the normal closed circuit position of the device, as shown more particularly at the left hand side of Figure 7, is received within an opening IS in the barrier wall l3. However, when the carrier is reversed top for bottom, as described above, the pin 20 which is mounted offset with respect to the center of the carrier [4 no longer registers with the opening is when the carrier is inserted, so that the end of the pin engages with the front surface of the barrier wall I3 to limit the position of the carrier so that the contacts will not engage, as more particularly shown at the right hand side of Figure 7, wherein the carrier and base are shown assembled in the open circuit position.

One feature of applicants invention lies in the improved and simplified means for supporting the electrical conductors on the base and as more particularly shown in Figures 5 and 6. Shown in these figures are the conductors or terminal straps 2| which are connected to the stationary contact elements I0 at the top of the socket II and the terminal straps or conductors 22 connected to the stationary contacts II) at the bottom of socket II. The ends of these strap conductors remote from the top and bottom of the nal for the socket fuse receptacle l2. When thus inserted, the conductor straps are guided by portions on the base to permit initial movement only vertically upward or downward and the studs 24 or 25 prevent such movement, so that the straps are rigidly maintained in place by the range or other equipment. The two top off terminals at the bottom of the base, designated by the numeral 26, are intended for tap off to any electrical equipment and go through only the main fuse in the left hand socket. The four smaller terminals at the bottom of the base are intended for branch circuits and tap off from the branch plug fuse sockets [2 which, in turn, are fed from the main fuses in the left hand socket.

Figure 6 shows the back connection of these elements, and as it is a back view, shows the parts as reversed from the position shown in the front views of Figures 3 and, 4. Here it is seen that the load or lower side of the main fuse socket at the right hand side of the back of the base (Figure 6) is connected with the line contacts of the range fuse socket, as represented by the lower contacts at the left hand socket, as by means of conductors 21 and 28. Connection is made to the plug fuse receptacles directly from the load side of the main fuses by means of the ultimate conductors 29, 22, 32, and 33, into which the fuse receptacle terminal studs 25 are threaded in'supporting relation. The conductor straps 22 and 33 are extended to the bottom of the base to form the tap off terminals 26. Upon the back wall of the enclosing box is supported a neutral conductor 34.

The operation of the enclosure will now be described. In normal operation, only the cover 4 is opened to provide access to the fuse carriers l4 and to the branch plug fuses; however, for wiring purposes, or other manipulations, the cover flaps 2 and 3 are also openable by loosening of studs 1. To provide greater access within the box for the drawing in of wires or the attachment of conduit, studs 6 are loosened and the supporting pan 5 and the base 9 supported thereon are bodily swung to the exterior of the box to entirely uncover the box interior. After the desired manipulations, the pan may be swung again into its interior position and studs 5 tightened, whereupon the base is securely mounted within the box. When the cover flaps 2 and 3 are in place they shield all parts within the box, except the fuse manipulating portions, from access. The operation of the carriers M to per form their switching function or to provide for inspection or replacement of the cartridge fuses mounted thereon, and the re-assembly of these carriers on the base in open circuit position, has been previously described.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims. What is claimed is:

1. In an electric circuit controlling device, a

base having a recess open at the front, stationary contacts near the back of the base and adjacent the top and bottom of the recess, a removable fuse carrier adapted to substantially close said recess and carrying on its back face cartridge fuse receiving means and contact portions adapted to co-operate with said stationary contacts, said carrier being provided with a ventilating opening therethrough to facilitate the dissipation of heat from within the recess,and a manually engageable handle on the front face of said carrier extending transversely thereof and at least partially interfering with free access through said opening into the recess.

2. In an electric circuit controlling device a base having a recess open at the front, stationary contacts near the back of the base and adjacent the top and bottom of the recess, a removable fuse carrier adapted to substantially close said recess and carrying on its back face cartridge fuse receiving means and contact portions adapted to co-operate with said stationary contacts, said carrier being provided with a ventilating opening therethrough to facilitate the dissipation of heat from within the recess, and an integrally molded handle on said carrier having a portion spaced in front of and substantially shielding said opening.

3. In an electric circuit controlling device, a base having a recess open at the front, two pairs of stationary contacts near the back of the base and arranged with the contacts of each pair adjacent opposite ends of the recess, a removable fuse carrier adapted to substantially close said recess and carrying on its back face two pairs of cartridge fuse receiving means and contact portions adapted to co-operate with said stationary contacts in the closed circuit position of the carrier, insulating formation which in at least the closed circuit position of the carrier substantially divide said recess into two compartments each of which receives one set of said cooperating pairs, said carrier being provided with two ventilating openings, one leading into each of said compartments, to facilitate heat dissipation therefrom, and an integrally molded handle on said carrier having a transversely extending gripping portion spaced in front of said openings and substantially shielding them.

4. In an electric circuit controlling device, a base having a recess open at the front, two pairs of stationary contacts near the back of the base and arranged with the contacts of each pair adjacent opposite ends of the recess, a removable fuse carrier adapted to substantially close said recess and carrying on its back face two pairs of cartridge fuse receiving means and contact portions adapted to co-operate with said stationary contacts in the closed circuit position of the carrier, insulating formations which in at least the closed circuit position of the carrier substantially divide said recess into two compartments each of which receives one set of said cooperating pairs, a part on the carrier received within a clearance portion in the insulating formation within the recess to permit full insertion of the carrier in its closed circuit position said part being positioned eccentrically of the center of the carrier so that when the carrier is inserted in the recess facing normally but out of its normal upright position the part will interfere with another part within the recess to prevent full insertion of the carrier in contact engaging position.

5. In an electric circuit controlling and protective device, a base having front and rear opening recesses, a plug switching unit adapted for insertion in said front opening recess and carrying switching elements and cartridge fuse receiving portions, a conducting connector strap disposed in said rear opening recess and having a switching element mounted thereon adapted to cooperate with a switching element on the plug, a ledge formed within said rear opening recess remote from the ends of the base and having a front facing supporting surface receiving one end of said connector strap in supporting relation, and a single screw means threaded into another portion of said connecting strap and completing the support thereof, removal of said screw means permitting the ready removal of said strap from its support on said ledge.

6. In an electric circuit controlling and protective device, an insulating base having front and rear opening recesses, a plug disposed in said front opening recess and carrying switching elements and cartridge fuse receiving portions, an end ledge on said insulating base having a front facing surface, an end slot into said rear opening recess adjacent said front facing ledge surface, a conducting strap disposed within said rear opening surface and against said front facing ledge surface, a ledge portion within said rear opening recess remote from the ends of said base and having a front facing supporting surface receiving and holding one end of said conducting strap, screw means extending through said end ledge and into said strap for supporting and holding the strap in position, and switching means mounted on the portion of said conducting strap within the recess for cooperation with a switching element on said plug.

'7. In an electric circuit controlling and protective device, an insulating base having front and rear opening recesses, a plug disposed in said front opening recess and carrying switching elements and cartridge fuse receiving means on the back face thereof, a plug fuse receiving recess in said base and opening to the front thereof, a conducting connector strap disposed in said rear opening recess and carrying a switching element adjacent to one end which cooperates with a switching element on said plug, a ledge within said rear opening recess remote from the ends of the base and having a front facing supporting surface receiving and holding said conducting strap adjacent said one end, and screw means extending through the portion of said insulating base forming the bottom of said plug fuse socket and threaded into said conducting strap and serving in cooperation with said ledge to firmly support the conducting strap and the parts associated therewith in position.

8. In an electric circuit controlling device, a base having a recess open at the front, stationary contacts adjacent the back of the base and adjacent the top and bottom of the recess, a removable fuse carrier adapted to substantially close said recess and carrying on its back face cartridge fuses and contact portions adapted to cooperate with said stationary contacts, insulating formations upon said carrier and within the recess which cooperate to divide the recess into two compartments, each of which receives cooperating sets of stationary contacts and contact portions, a pin projecting from the insulating formation on the back face of said carrier and I normally disposable within an opening in the insulating formation within the recess to permit the full circuit closing insertion of the carrier within the recess, said pin being spaced away from the center of said carrier so that when the carrier is inserted in the recess facing normally but out of its normal upright position said pin will interfere with the insulating formation within the recess to prevent the full insertion of the carrier into the recess.

9. A switch contact supporting means comprising a base provided with openings therethrough, portions of said base overlying some of the sides of the opening, other portions of said base underlying other of the sides of the opening, the overlying and underlying portions of said base being of such thickness and so separated as to form slots therebetween adapted to accommodate a bar member and maintain it in position against movement transverse to the base, the portion of the opening not covered by either the overlying or underlying portions of said base being adapted to register with a switch receiving contact on a bar member.

10. A switch comprising a contact housing provided with a base and side walls therefor, bar member provided with switch receiving contacts on one end thereof, openings in said base, portions of said base overlying some of said openings, portions of said base underlying the same openings,

said overlying and underlying portions of said base being spaced and of such thickness as to form a slot therebetween adapted to accommodate said bar members, the portion of said base not covered by underlying or overlying portions registering with the switch receiving contact on the bar members, a switch blade supporting means, and switch blades secured thereto and adapted to be inserted through openings in the base and into the switch receiving contacts on the bar member.

11. A fuse cutout switch comprising switch blades, a switch blade supporting means, a contact supporting base, straight slots in said base, bar members provided with switch blade receiving contacts supported by underlying and overlying portions of the base, plug fuse sockets supported by said base and having one contact thereof electrically connected to said bar members, the switch blades being provided with portions thereof adapted to receive and hold a fuse terminal and to exert a clamping action thereon when said switch blades are inserted in the switch blade receiving contacts.

12. In a fuse cutout switch, a contact supporting base, two pair of oppositely disposed openings through said base, bar members partially disposed in said openings and positioned by extensions of the base above and below said openings, said bar members provided with switch blade receiving contacts adjacent the end positioned in the openings and terminal connections adjacent the other end, a pair of fuse sockets positioned above one pair of bar members between the switch blade receiving contact and the terminal connection and electrically connected thereto.

' JOHN G. JACKSON.

RALPH H. KINGDON. 

